It's the game of the season so far on Saturday night at Stamford Bridge as resurgent Manchester United under Louis Van Gaal, take on Jose Mourinho's league leaders with both teams bang in form. Gary Neville believes this is United's toughest test yet.

Who would have thought we would be saying what we are about Manchester United of late compared to the first few months of the season? Varied tactics, players not performing and a team struggling to find it's identity under the new regime, United looked a team bang in trouble.

You have to hand it to Van Gaal and his staff, they have turned their fortunes around and are in third place, hot on the heels of Arsenal having all but confirmed their place in the top four. Playing well, scoring goals and producing levels of performance that some have compared to the glory days of Sir Alex, United are a very real threat to Chelsea this weekend.

However, Gary Neville believes that despite impressive victories over City, Liverpool and Tottenham of late, this is the real test of their credentials. He said:

"The tests have been Liverpool and City.

This is another test. They have proven themselves, but this is the best team in the country and to go to Stamford Bridge is the toughest test."

It will be interesting to see firstly how both managers set their teams up ahead of the game and secondly, who has the players to make the difference in one of the biggest games of any Premier League season?

Chelsea have not been anywhere near their best over the last two months or so but keep winning games and picking up points. Pundits and Reporters would have you believe that Chelsea are on a poor run but if you call eight wins and three draws from the past eleven games a bad run, then so be it.

Both teams have the ability to hurt you. Both teams have big players that can make the difference and produce a moment of magic that wins you the game. I personally believe that this Saturday it comes down to the defensive line of both sides and this is where Chelsea will win it.

I agree that United deserve all the plaudits they have received of late because of the fantastic run of results they have had. However, I believe their defence is far from solid and against the right system, with the right players that can hurt them, United can be opened up time after time and Chelsea will be the team to do exactly that to beat them.

Gary Neville knows a thing or two about Football and I agree for United this will be their toughest test and maybe one that exposes their frailties in defence.